ThreeJs 如何在球体的直径上画一条线？

Question

假设我有一个这样的球体：

var geometry = new THREE.SphereGeometry( 1, 32, 32 );
window.sphere = new THREE.Mesh( geometry, material );
scene.add( window.sphere );

然后我将如何围绕球体的直径画一条线？最好平行于 x 轴。这里的最终目标是将这样的线与文本结合使用来说明大小（例如，这个球体有 10 米宽）。

Answer 1

你可以使用这个技巧：

var material = new THREE.MeshBasicMaterial( { color: 0xaaaaaa } );
var geometry = new THREE.SphereGeometry( 32, 32, 32 );
var sphere = new THREE.Mesh( geometry, material );
scene.add( sphere );

var geometry = new THREE.TorusGeometry( 31.9, 0.16, 64, 100 );
var material = new THREE.MeshBasicMaterial( { color: 0xffff00 } );
var torus = new THREE.Mesh( geometry, material );
torus.rotation.x = Math.PI/2;
scene.add( torus );

http://jsfiddle.net/10hemttk/36/

Upd. 嗯，这样比较正确：

var rad = 32,
    delta = 0.05,
    segs = 64,
    material = null,
    geometry = null,
    circle = null,
    sphere = null;

material = new THREE.LineBasicMaterial( { color: 0xffff00 } ),
geometry = new THREE.CircleGeometry( rad+delta, segs ),    
geometry.vertices.shift();
circle = new THREE.Line( geometry, material );
circle.rotation.x = Math.PI/2;
scene.add( circle );

material = new THREE.MeshBasicMaterial( { color: 0xaaaaaa } );
geometry = new THREE.SphereGeometry( rad, segs, segs );
sphere = new THREE.Mesh( geometry, material );
scene.add( sphere );

ThreeJs 如何在球体的直径上画一条线？

How to draw a line on the diameter of a sphere in ThreeJs?

javascript

three.js